MINIMALLY INVASIVE ANTERIOR HIP REPLACEMENT SURGERY: THE “BIKINI INCISION” TECHNIQUE

By Prof. Pierantonio Gardelin – Orthopedics and Traumatology Specialist – Columbus Clinic Center

What has changed in the hip replacement surgery approach?

«In recent years, hip replacement surgery has reached very high standards, both in terms of risks of complications and of post-surgery recovery. Also the implant itself, which was once estimated to wear out or loosen after 15 years, is now likely to need a revision surgery (and therefore replacement) after even 30-40 years, thanks to the use of new materials, medical advances and modern surgery techniques, although there are factors that unfortunately cannot be overlooked. The surgeon must take numerous precautions during the surgery: not only is it fundamental to ensure utmost safety in the operating room, but it is also necessary to be as less invasive as possible (with an eye also to the aesthetic aspect), without neglecting the ubiquitous possibility of a failure of the surgery itself.

Indeed, the minimally invasive technique represents a valid alternative for patients (especially sportspeople) for many reasons:

  • It guarantees rapid recovery;
  • Functional and visual result that fully meets the patient’s expectations;
  • Reduced complications such as infections (reported in 0.3% of hip and knee implant cases especially in patients with risk factors such as diabetes, obesity, immunosuppression, alcohol abuse or smoking) or trauma (falls, fracture of the femur) which may lead to repeat surgery and cause further stress to the patient».

Unlike traditional surgery, the AMIS technique (Anterior Minimally Invasive Surgery) is acknowledged for its many advantages, especially for the patient. Among these:

  • It is minimally invasive: the surgeon accesses the hip joint through a small surgical incision, with no damage to the surrounding muscles and bones.
  • It allows to spare muscle tissue: thanks to the use of this access route, the original muscle is kept in place as the hip joint is reached by blunt dissection (i.e. by splitting rather than cutting the muscles); the anterior access procedure is associated with a low risk of dislocation (<1%), that is, when the implant moves out of place*.
  • Bone cut: through this procedure, a less-aggressive short stem is implanted inside the femur bone and therefore – in case of future revision – the surgeon will benefit from the previous work to implant a new prosthesis without difficulty».

 

The evolution of this access route is known as the BIKINI incision. Why this name?

«A further variation on the anterior approach for hip replacement by blunt dissection involves an inguinal incision, done within a pre-existing skin fold of the “bikini line” (the groin crease), which makes the scar less visible and easily hidden when wearing a swimsuit. And it is precisely for this characteristic that the technique takes the curious name of Bikini, much appreciated by the female patients!

However, when it comes to choosing the right technique, there are some contraindications for certain subjects. Indeed, obesity can make the surgery technically difficult; while the more developed muscle mass in male patients can increase the risks of perioperative complications. In these cases, the surgeon may opt for a classic longitudinal incision, thus, a traditional anterior hip replacement surgery.

This technique, the Bikini incision, is performed by very few surgeons because of the difficulties that the surgery involves».

 

What are the post-operative indications to follow?

«Following AMIS, it is advisable to use crutches for the first few days until the patient adjusts to the correct posture while walking; subsequently, a full load is restored to the operated leg with no mobility limits related to the risk of a possible dislocation.

When crutches are no longer needed (within a week or about 20 days), patients may resume driving if they can. As for sports, this is one of the most frequent reasons why our patients undergo this type of surgery: some of them, in fact, are not satisfied with just being able to walk well again after their surgery but also, and especially, they expect to return to their sports practice and performance. We have performed the minimally invasive technique on many young sportspeople (40-50 years old) even though, normally, the target patient eligible for this type of surgery is around 65-70 years old. I personally recommend the AMIS technique also for older subjects, not only because it enables them to stand safely from the first day after surgery with the help of a physiotherapist, but also because this would dispel the myth that innovative procedures are not suitable for patients over the age of 70, due to their advanced age. With regard to physical activity, the patient is potentially allowed back to any type of sport, from those including changes of direction and jumps, to others like running or swimming. It is however advisable to avoid high-impact sports (e.g. football, martial arts) in order to ensure a longer lifespan of the implant over the years, especially if the sport is played at a professional level».